The invention relates to a multiple blank, which can be separated into individual blanks for electronic components, in particular surface acoustic wave (SAW) components, which are each suitable for contact to be made with chips in the flip-chip technique on the individual blanks and for contact to be made with the individual blanks in the SMD (surface mounted device) technique, using external connections. In addition, the invention relates to a method of building up bumps, solder frames and the like on the multiple blank.
Building up the bumps needed for contact to be made with chips in the flip-chip technique, also referred to as solder balls, and the solder frames needed for fixing the chip metal caps onto ceramic and printed circuit board multiple blanks has hitherto been carried out by means of screen printing or stencil printing.
The prior art method of printing-on bumps and solder frames entails expensive stencils, which are different for each electronic component type, and therefore also type-specific special tools for producing the stencils.
Additional problems in stencil printing occur as a result of distortion of the substrate material, for example of the ceramic of the multiple blank and therefore of the individual blanks, since in all these cases the desired exact geometric arrangement of the bumps on the individual blanks is not possible. This is equally true, although with less damaging effects, of the solder frames and of possible spacers to ensure the necessary spacing between the chip and individual blank or substrate.
The object of the invention is to provide a multiple blank of the type mentioned above, which overcomes the above-noted deficiencies and disadvantages of the prior art devices and methods of this kind, and which provides a multiple blank that can be separated into individual blanks and which eliminates the disadvantages previously mentioned. The device should be less complicated and permit a method of building up the bumps and solder frames and, if it is necessary, also the spacers and the like which, irrespective of the substrate material of the blank, always exactly ensures the usually type-specific geometry of the bump, solder frame, and the like.
With the above and other objects in view there is provided, in accordance with the invention, a multiple blank assembly, comprising:
a plurality of layers defining a multiple blank separable into individual blanks for electronic components, in particular surface acoustic wave (SAW) components, the individual blanks being configured to be mounted in SMD technique using external connections and to have mounted thereon chips in flip-chip mounting technique;
first and second networks integrated between the layers of the multiple blank and respectively connected to a first connecting terminal and a second connecting terminal;
the multiple blank being formed with first metalized areas for each individual blank for making contact with bumps between the first metalized areas and the chips, the first metalized areas of the multiple blank being interconnected via the first network and to the first connecting terminal; the multiple blank being formed with second metalized areas connected via the second network to the second connecting terminal; and
wherein the first and second metalized areas are configured for building up mutually different electronic components from mutually different materials.
In accordance with an added feature of the invention, the connecting terminals of the networks are disposed at a lateral edges, i.e, an end face, of the multiple blank.
In accordance with an additional feature of the invention, the first and second connecting terminals are in contact with each other.
In accordance with another feature of the invention, the multiple blank is a multilayer ceramic multiple blank or a multilayer printed circuit board with dividing faces between the layers, and the networks are disposed at the dividing faces between the layers.
In accordance with a concomitant feature of the invention, a plurality of SMD contact elements that are connected to the first contact areas via plated-through holes are formed in the multiple blank.
With the above and other objects in view there is also provided a production method, which comprises:
providing a multiple blank assembly as detailed in the foregoing text and defining the metalized areas for bumps, solder frames, spacers, and the like; and
depositing metallic layers by electroplating on the metalized areas, and thereby connecting up the networks for elements to be produced differently at separate times and depositing different metals.
In accordance with again an added feature of the invention, SnPb alloys are electroplated onto the metalized areas of the multiple blank.
In accordance with again a further feature of the invention, bumps are built up by electroplating SnPb layers onto the first metalized areas of the multiple blank, and subsequently heating the SnPb layers to their melting point.
In accordance with again another feature of the invention, the first metalized areas are predefined by a clear width of the plated-through holes in the multiple blank, and the first metalized areas are enlarged by applying thereon a sequence of layers of metals and subsequently depositing metal layers needed to build up bumps by electroplating and heating the metal layers to their melting point.
In accordance with a preferable feature of the invention, a sequence of layers Wxe2x80x94Nixe2x80x94Au is deposited by screen printing, electroplating, and/or electroless deposition.
In other words, the above objects are satisfied with multiple blanks that have, for each individual blank, metalized areas to make contact with bumps, the areas being located on a network which is integrated in the multiple blank and leads to a connecting terminal.
Further metalized areas for building up solder frames for the metal caps for chips, optionally for spacers and other necessary elements, are in each case located on additional networks which are integrated in the multiple blank and lead to corresponding further connecting terminals.
On the other hand, integrated networks and, consequently their electrical connection to connecting terminals, are dispensed with in all those cases in which conductive areas are not electroplated, that is to say are not intended to be provided with bumps.
By means of these multiple blanks, the metallic layers desired for the bumps, solder frames and the like, for example SnPb layers, can be deposited by electroplating on the metalized areas, the connecting terminals of the individual networks being connected together or activated separately at time intervals, depending on whether identical or different metallic layers, layer compositions and layer thicknesses are required for the bumps, solder frames and the like.
The layer thickness can be set very precisely via the quantity of charge, that is to say the product of current intensity and time. Distortion problems of the type mentioned in the case of stencil printing do not occur. Stencils and the production of corresponding, type-specific special tools for this purpose are likewise dispensed with.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a multiple blank for electronic components, in particular surface acoustic wave components, and method of building up bumps, solder frames, spacers and the like on the multiple blank, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.